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FGUS71 KCLE 191830
ESFCLE
OHC005-007-033-035-043-055-063-075-077-083-085-093-095-099-101-
103-117-123-133-139-143-147-151-153-155-169-173-175-PAC039-049-
052045-
WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE CLEVELAND OH
125 PM EST THU FEB 19 2015
...WINTER/SPRING FLOOD OUTLOOK NUMBER 4...
...THE FLOOD THREAT IS EXPECTED TO BE NEAR NORMAL ACROSS
NORTHWEST PENNSYLVANIA AND NORTHERN OHIO THROUGH EARLY
MARCH...
A NORMAL FLOOD POTENTIAL MEANS OCCASIONAL FLOODING COULD OCCUR
WITH WATER LEVELS HAVING MINOR IMPACTS. THIS IS THE FORTH ISSUANCE
OF THE WINTER AND SPRING FLOOD OUTLOOK ISSUED BY THE NATIONAL
WEATHER SERVICE IN CLEVELAND. FLOOD OUTLOOKS ARE ISSUED BIWEEKLY
DURING THE WINTER AND EARLY SPRING TO SUMMARIZE CURRENT CONDITIONS
AND ASSESS THE POTENTIAL FOR FLOODING ACROSS NORTHERN OHIO AND
NORTHWEST PENNSYLVANIA.
FACTORS TO CONSIDER WHEN ASSESSING FLOOD POTENTIAL THIS TIME OF
YEAR ARE CURRENT RIVER AND RESERVOIR LEVELS...SNOW PACK DEPTH AND
WATER CONTENT...ICE COVERAGE ON AREA RIVERS AND THE LAKE...SOIL
MOISTURE...AND WIDESPREAD HEAVY RAINFALL POTENTIAL.
...OVERVIEW...
THE WEATHER PATTERN FOR THE SHORT TERM FORECASTS SHOWS NO NOTABLE
THAWS OR RAIN EVENTS EXPECTED...THEREFORE IT IS UNLIKELY THAT THE RIVERS
WILL EXCEED THEIR BANKS. THE ONLY EXCEPTION COULD BE CAUSED BY THE
DEVELOPMENT OF ICE JAMS WHICH CAN CAUSE FLOODING IN ISOLATED
SITUATIONS.
...PRECIPITATION AND TEMPERATURE FORECASTS...
THE OUTLOOKS THROUGH LATE FEBRUARY INTO EARLY MARCH SHOW AN
ANOMALOUSLY COLD PATTERN. MULTIPLE AREAS OF ARCTIC HIGH PRESSURE ARE
EXPECTED TO MOVE OVER THE CENTRAL AND EASTERN U.S. DURING THE
PERIOD. AN AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OVER THE
WEEKEND STRETCHING FROM THE OHIO VALLEY TO NEW ENGLAND. NEXT WEEK
THERE ARE INDICATIONS OF ADDITIONAL CLIPPER SYSTEMS MOVING OUT OF
CENTRAL CANADA AND THE NORTHERN PLAINS. TOWARDS THE END OF OUT TWO
WEEKS THE SUGGESTED WEATHER PATTERN BECOMES MORE ACTIVE IN THE
PACIFIC NORTHWEST...WHICH CAN TRANSLATE EAST AND IMPACT THE GREAT
LAKES/OHIO VALLEY REGIONS. OVERALL THE OUTLOOKS CALL FOR BELOW
NORMAL TEMPERATURES AND NEAR NORMAL PRECIPITATION FOR THE NEXT 6 TO
10 DAYS. SPRING OUTLOOKS SUGGEST NORMAL TEMPERATURES AND NEAR NORMAL
RAINFALL.
...SNOW COVER...
AT THE TIME OF THIS ISSUANCE THE SNOWPACK WAS HEAVIEST ACROSS THE
SNOWBELT WHERE THE AVERAGE DEPTH WAS ONE TO TWO FEET. ELSEWHERE THE
SNOWPACK HAS COMPACTED TO EIGHT INCHES OR LESS. AREAS SOUTH OF THE
ROUTE 30 CORRIDOR HAVE NO NOTABLE SNOWPACK. THE WATER EQUIVALENT IN
THIS REGION IS NEGLIGIBLE. FROM CLEVELAND WEST TO TOLEDO THE SNOW
WATER EQUIVALENT IS ONE AND A HALF INCHES OR LESS. IN THE SNOWBELT
THE WATER EQUIVALENT IS BETWEEN TWO AND FOUR INCHES. THE SNOWPACK
FOR THIS TIME OF YEAR IS RUNNING ABOVE NORMAL...AND IT IS EXPECTED
TO CONTINUE TO GROW AS NO NOTABLE THAWS ARE FORECASTED. THERE WILL
BE A WARMUP OF THE SNOW ON THE 22ND WHICH WILL COMPACT THE SNOWPACK
EVEN MORE BUT KEEP THE WATER EQUIVALENT RELATIVELY UNCHANGED.
...ICE COVERAGE...
THE ICE ALONG AREA RIVERS CONTINUES TO GROW. THE RIVER STAGES
REMAIN UNDER THE 50TH PERCENTILE WHICH IS ALLOWING FOR LARGE ICE
SHEETS TO DEVELOP. AS IF OFTEN THE CASE THIS TIME OF YEAR...NUMEROUS
RIVER GAGES ARE BEING EFFECTED BY THE COLD AND ICE CONDITIONS AND
ARE REPORTING INACCURATE STAGE READINGS. RIVER OBSERVERS SHOULD
REPORT SIGNIFICANT ICE JAMS TO THE LOCAL AUTHORITIES WHO WILL INFORM
THE NATIONAL WEATHER SERVICE.
THE ICE COVERAGE ON LAKE ERIE IS RUNNING ABOVE NORMAL FOR THIS TIME
OF YEAR ACCORDING TO THE GREAT LAKES ENVIRONMENTAL RESEARCH LAB ICE
FORECAST MODEL. THE LAKE IS 97.8% ICE COVERED WITH AN AVERAGE
THICKNESS AROUND A FOOT IN THE NORTH AND A FOOT AND TWO FEET IN THE
CENTRAL AND SOUTHERN PARTS OF THE BASIN. OUTLOOK IS FOR ADDITIONAL
ICE GROWTH OVER THE NEXT TWO WEEKS.
...CURRENT RIVER AND RESERVOIR LEVELS...
ALL BASINS ACROSS THE REGION ARE RUNNING AT NORMAL STREAM FLOWS. THE
MAJORITY OF THE LOCAL RESERVOIRS ARE RUNNING AT OR SLIGHTLY BELOW
THE IDEAL WINTER POOL LEVELS. THE AMOUNT OF REMAINING FLOOD STORAGE
REMAINS HIGH WITH ALL RESERVOIRS REPORTING LESS THAN 5% OF USAGE AT
THE TIME OF THIS ISSUANCE.
...SOIL MOISTURE...
TOP SOILS REMAIN FROZEN AND SNOW COVERED. THE SPRINGSBORO
PENNSYLVANIA SOIL TEMPERATURE READING SHOWS THE FROST DEPTH TO SIX
INCHES. WITH THE GROUND FROZEN AND THE SNOWPACK GROWING THE
POTENTIAL FOR RAPID RUNOFF AND FLOODING WILL REMAIN A THREAT IN ANY
FUTURE RAIN OR SNOW MELT EVENTS.
...LONG TERM OUTLOOKS...
THE LONG-RANGE RIVER OUTLOOKS AND THE PROBABILITY OF EXCEEDING
FLOOD STAGE OR THE CHANCES OF FLOODING RELATIVE TO NORMAL AT
SPECIFIC FORECAST POINTS DURING THE NEXT 90 DAYS IS NEAR TO ABOVE
NORMAL. THE ENSO OUTLOOK IS PREDICTING A 50-60% CHANCE OF EL NINO
DEVELOPING DURING THE NEXT COUPLE OF MONTHS BUT WITH A DECREASING
CHANCE INTO SPRING AND SUMMER. THE LONG TERM TEMPERATURE OUTLOOKS
SUGGEST TEMPERATURES AT OR ABOVE NORMAL THROUGH SPRING. THE
PRECIPITATION OUTLOOKS SHOW MORE NEUTRAL CONDITIONS THROUGH WINTER.
...FLOOD POTENTIAL SUMMARY AND OUTLOOK...
IN SUMMARY...DESPITE THE FROZEN GROUND COVER AND THE ABOVE NORMAL
SNOW PACK IN THE SNOWBELT THERE DOESN`T APPEAR TO BE ANY CATALYST TO
PRODUCE RAIN OR SNOWMELT IN THE NEXT TWO WEEKS. THE FLOOD
CHANCES FOR THE REST OF THE WINTER WILL BE HEIGHTENED IF THE
SNOWPACK IS UNABLE TO GRADUALLY MELT BEFORE SPRING. HOWEVER BASED ON
CLIMATOLOGY AND EXPECTED NORMAL PRECIPITATION THIS SPRING THE
OUTLOOK FOR FLOODING THE REST OF THE WINTER IS NEAR NORMAL.
CLIMATOLOGY FAVORS MARCH AND APRIL AS THE MOST FREQUENT PERIOD FOR
FLOODS.
THE NEXT WINTER/SPRING FLOOD OUTLOOK WILL BE ISSUED ON MARCH 5TH.
$$